1. Field of Invention
The present invention relates, in general, to the field of methods, and associated equipment, for automatic and sequential loading of objects, particularly for the purpose of placing a decoration on each object.
More precisely, the invention relates to a method for automatic and sequential loading of objects of a predetermined type onto a holding device, where each object and the holding device having first and second respective axes of rotation and first and second respective locators of rotation about these respective axes. The loading of each object onto the holding device leads to a contact of the object with the device, to an alignment of the first and second axes, and to an angular setting of the first and second locators in a predetermined relative angular position. The method comprises the steps of carrying out a movement of each object until it is in contact with the holding device and selectively carrying out a relative rotation of the object and of the holding device about the first and second axes of rotation to achieve said setting position.
2. Prior Art
When a user desires to decorate a packaging object made of glass or organic material (flask, carafe, bottle or cosmetic pot for example), via a conventional method such as screen-printing or pad-printing, the user is faced with the problem of setting the decoration to be placed with, on the one hand, the geometric particular features of the object and, on the other hand, decorations or decoration roughs that may already exist, knowing that the objects have a random angular position.
As examples:                the placement of the decoration must be situated on a clearly defined zone of the object, such as a flat, or must be positioned relative to a mechanical locator situated on the object (locating notch or pins) or else on a preexisting decoration element such as, a reserve element (transparent window) in a satin finishing or a lacquering;        the decoration must be made on a zone in which the object has no defect, for example the join mark of molds called a “mold joint” on glass articles.        
In current machines (items of equipment), the setting is essentially mechanical, carried out by making a part of the decorating machine, called the skirt, fixedly attached to the object to be decorated.
The angular setting is carried out by a retractable pin, mounted on a spring, fixedly attached to the skirt, which sets itself in a notch made on the bottom of the object or by another blocking device on a notch positioned on the body of the object. Once the object is immobilized relative to the skirt, the latter is placed in rotation to bring the object into the angular position suitable for the placement. Alternatively, there are implementations in which the skirt is fixed and the object is placed in rotation.
Mechanical setting has the following disadvantages.
When the skirt and the object are placed in relative rotation, the friction between the movable elements (skirt and pin) and the fixed elements (bottom of the object) leads on the one hand to a deterioration of the appearance of the bottom in the case of objects coated with a varnish, a lacquer, or a chemical satin finish. It also leads to wear of the skirt and/or the pin, which may occur after several hours of operation, which causes a loss of quality of angular location, and even a breakage of the object, which leads to the cost of machine stoppage and of replacement parts.
These elements may also lead to limiting the speed of rotation of the skirt and hence to reducing the overall rate of production. Furthermore, this type of method leads to a limited precision, because of the mechanical tolerances of the object, of the pin and of the notch, these tolerances being able to lead, by accumulation, to nonconformities.